1. Field of the Invention
The present invention is related to a disc drive.
2. Description of the Prior Art
Disc drives which carry out playback or recording/playback of an optical disc such as a CD-ROM, a CD-R, a DVD or the like can be used in a horizontal arrangement in which an optical disc is held in a concave portion of a disc tray which is in a roughly horizontal state, or in a vertical arrangement in which the disc tray is arranged in a roughly vertical state.
FIG. 11 is a plan view showing a prior art optical disc drive which can be used in a vertically arranged state, FIG. 12 is a partial cross-sectional side view (showing the state in which the disc tray is moved to the ejection position) of the optical disc drive shown in FIG. 11, and FIG. 13 is a partial cross-sectional side view showing another example structure of a prior art optical disc drive.
As shown in FIG. 11, the prior art disc drive 900 which can be used in a vertically arranged state includes a main body 920 in which a disc drive unit (not shown in the drawings) equipped with an optical pickup and the like are housed, and a disc tray 910 which is movable between a position (loading position) for loading an optical disc D and a position (ejection position) for ejecting the optical disc D with respect to the main body 920.
The main body 920 is comprised from a roughly box-shaped casing 922, a top plate (cover) 923 and a front bezel 940 provided on the front of the casing 922. An opening 941 is formed in the front bezel 940. The disc tray 910 is moved between the ejection position and the loading position through the opening 941.
A concave disc holding portion 911 for holding an optical disc D is formed in the disc tray 910. A plurality of disc holding members (hooks) 913 are provided on the periphery of the disc holding portion 911 so that they protrude above the disc holding portion 911. The disc holding members 913 are provided for holding an optical disc D placed in the disc holding portion 111 in a freely rotatable manner from the side of the upper surface of the optical disc when the disc drive 900 is used in a vertically arranged state.
In this regard, when these disc holding members 913 are provided on the disc tray 910, there is a case that a part of the optical disc D is accidentally placed on top of one or more disc holding members 913 (see FIG. 11) when the optical disc D is placed in the disc holding portion 911. In such an accidental state, when the disc tray 910 is moved toward the loading position as it is, the optical disc D is conveyed to the inside of the main body 920 in an inclined state with respect to the disc holding portion 911 (i.e., a state in which a portion of the optical disc D protrudes out of the disc holding portion 911). In this case, when the disc tray 910 is moved toward the ejection position from the loading position, the optical disc D becomes caught near the opening 941 (at the upper side rear end of the front bezel 940), and this makes it impossible to move the disc tray 910 (see FIG. 12).
In order to avoid such an accident described above, in the case where such disc holding members 913 are provided on the disc tray in the prior art structure, a protruding member 930 having a rectangular parallelepiped shape is provided on the inside (bottom) surface of the top plate 923 at a position near the opening 941 of the front panel 940. When such a protruding member 930 is provided, even in the case where the disc tray is moved toward the loading position in a state where a portion of the optical disc D is placed on one or more disc holding members 913, the protruding member 930 pushes the optical disc D toward the disc holding portion 911, so that the optical disc D and the disc holding members 913 on which the portion of the optical disc D is lying are bent to the bottom surface of the disc holding portion 911. Accordingly, when the disc tray 910 is moved to the ejection position in this state, the protruding member 930 prevents the optical disc D from being caught near the opening 941, and this makes it possible to move the disc tray 910 to the ejection position.
However, when the top plate 923 is provided with such a protruding member 930 having the rectangular parallelepiped shape, the air flow (i.e., the flow of air) generated at the time the optical disc D is rotated (at high speed) changes abruptly near the protruding member 930 so that the optical disc D is pushed (downward in FIG. 13) toward the disc holding portion 911. Consequently, the recording surface of the optical disc is shifted away from the focusing position of the laser light emitted from the optical pickup, and this has an adverse effect on the recording and playback characteristics. Further, when the spindle motor for rotationally driving the optical disc D reaches a specific rotation number, the optical disc D will resonate with the vibration of the spindle motor. In this case, when the downward force described above is applied to the optical disc D, the inclination of the optical disc D will become even larger, and this results in significantly lowering the recording and playback characteristics of the optical disc D.